Mercury registered a sharp fall in Haryana and Punjab after light rains lashed parts of the two states for the third consecutive day on Thursday.According to MeT office, the temperature dropped by up to nine notches in the region giving much needed respite to people from the hot weather conditions.Chandigarh, which received light showers earlier in the day, had a pleasant day at 31.7 degrees Celsius, seven notches below normal, the MeT office said.